Abstract:Abstract：The authors have constructed a new lithospheric structural model of the Qinling orogen by reprocessing and reinterpreting the seismic reflection profile from Yexian to Nanzhang and integrating and using the geophysical and geochemical data from seismic profiles for petroleum exploration, magnetotelluric sounding, heat flow and gasometry. The following major structures of varying ages have been recognized for the crust under the Qinling orogen：(1) crocodile structure formed by subduction of the North China craton beneath the Qinling microplate in the Caledonian period;(2) negative flower structure composed of a number of huge thrust faults centering around the Nanyang area formed by ramping-up, strike-slip motion and soft collision of the Yangtze craton and Qinling microplate during the Indosinian-Yanshan;(3) a dome of crystalline basement consisting of alternating orthogneiss and paragneiss formed after the Cretaceous; and (4) folded basement formed by nearly transparent Proterozoic low-grade metamorphic strata, overlying the crystalline basement. After the Cretaceous, as was the case with other areas in eastern China, a mushroom cloud-shaped structure was formed in the lithospheric mantle under the Qinling area due to the uplift of the asthenosphere and the lithosphere was reactivated, thus seriously affecting the tectonic evolution.

Abstract:Abstract：Early Cretaceous intermediate-acid intrusive rocks in eastern Anhui are composed of a quartz diorite, quartz monzodiorite, granodiorite and monzogranite association, belonging to the high-K calc-alkaline series. They are characterized by higher Al2O3, Sr, Sr/Y and La/Yb ratios enrichment in LREE and LILE, depletion in HREE, Y and Yb, weak Eu negative or positive anomalies, higher (87Sr/86Sr)i and lower εNd (t). Compared with most adakitic rocks in eastern China, these rocks have higher Mg# values, MgO and Cr and Ni contents. Our study suggests that：(1) intermediate-acid intrusive rocks in eastern Anhui might be derived from partial melting of the delaminated lower continent crust and its subsequent interaction with mantle peridotite during the rise of the magma, leaving garnet as a residual phase; and (2) the area of eastern Anhui experienced a crustal thickening process controlled by compressional structure of the Tethyan tectonic domain in the early Yanshanian, and, large-scale sinistral strike-slip movement of the Tanlu fault influenced by Pacific tectonic domain in the Early Cretaceous was the main factor responsible for delamination of the lower crust. Intermediate-acid intrusive rocks in eastern Anhui are petrological records of transition from the Tethyan tectonic regime to Pacific tectonic regime during the Mesozoic.

Abstract:Abstract：The paper reviews the major progress in the study of adakites in China, discusses the reason why so many papers on adakites have been published in China, summarizes the contribution and remaining problems of the adakite study and explores the present problems and future direction in the study. The author thinks that the study of adakites in China is on the upswing, which has been one of focuses of adakite study worldwide. However, generally the research level is not high though many papers have been published. Many questions and phenomena in the field remain unknown. The following are potentially key topics for future studies: (1) the origin of Mesozoic C-type adakite in eastern China; (2) the uplift mechanism of the eastern China Plateau in the Mesozoic; (3) the relationship between the adakite formation and uplift of the Qinghai-Tibet Plateau, and (4) the relationship between C-type adakite and porphyry Cu-Au mineralization.

Abstract:Abstract：The authors used the field data, seismic data, coal field drilling data and paleontological data to compile and analyze the representative stratigraphic division schemes for the Dunhua basin-coal prospect area at peripheries of the Songliao basin, and got the following understandings： (1) the age of the Huichun Formation is Eocene-Oligocene;(2) the Upper Cretaceous Longjing Formation may not exist in the basin; (3) the upper member and lower member of the so-called Mao'ershan Formation should be assigned to the Quanshuicun Formation and Changcai Formation;(4) the Dalazi, Quanshuicun, Changcai and Tuntianying formations do exist in the basin, of which the Dalazi Formation and Changcai Formation might be Early Cretaceous Aptian-Albian and Berriasian-Aptian in age respectively according to the lithostratigraphic and biostratigraphic correlation between the Dunhua basin and its neighboring basins;(5) the wrong uses of some local formation names at several sites of the basin are revised; and (6) a stratigraphic sequence is established in the Dunhua basin, which may be used for reference at present.

Abstract:Abstract：In most times of the Early Triassic Feixianguanian age (from phases 1 to 3), the northeastern Sichuan basin was in an environment of isolated carbonate platforms surrounded by a deep sea trough and formed by extensional faulting during the evolution of the South Qinling Mountain ocean. Concomitantly with the sea-level change, gradual closing of the Kaijiang-Liangping sea trough and eastward migration of the Chenkou-Exi sea trough, various isolated carbonate platform subfacies moved and were transformed, and finally the isolated carbonate platforms were transformed and amalgamated into a unifying large-scale land platform in northeastern Sichuan from the late part of the third phase to the early part of the fourth phase of the Feixianguanan age. On the basis of the regional geological setting and sedimentary characteristics (lithology character, paleontology, sedimentary structure and logging), the lagoon (including evaporative lagoon, restricted lagoon, semi-restricted lagoon and point beaches), platform-margin oolitic beach, slope and sea trough subfacies. A stereoscopic depositional model of isolated platforms was constructed and the distribution and evolutionary process of sedimentary facies from phases 1 to 3 of the Feixianguanan age were analyzed. Finally the authors analyzed the migration of the platform-margin oolitic beach facies belt that had conditions for the formation of good reservoirs in the late stage, inhomogeneity and log and seismic characteristics of the reservoirs and control of sedimentary facies on the distribution of oolitic beach gas reservoirs and made seismic lateral distribution forecast for the areas in platform-margin oolitic beach facies which are expected to become new breakthrough areas of gas exploration.

Abstract:Abstract：In the Qintong subbasin, the fault system is well-developed, and the faults controlling petroleum accumulation include faults F1, Ⅲ, F2 and F3 and their branch faults, which divide the fault steps into the Zhuzhuang wrench fault belt in the north and Caoshe wrench fault belt in the south. Based on the quantitative evaluation of the vertical and lateral sealing capacities of the faults, combined with the history of hydrocarbon generation and expulsion, distribution of oil sources, formation stage of petroleum accumulations and tracing analysis of pyrrolic nitrogen compounds, there is appreciable difference in sealing capacities of faults Ⅲ, F2 and F3 in different study areas. In the Zhuzhuang fault belt, the vertical sealing capacity of fault Ⅲ is good and cannot act as conduits of petroleum migration; so in the Jiaodunzi area, the oil was mainly derived from source rocks of the fourth member of the Funing Formation, but there are no contributions from the second member of the Funing Formation and the Taizhou Formation. The activity of fault F3 is short-continued and its lateral sealing capacity is poor; so this fault is not a conduit of petroleum migration either. By contract, fault F2 is long-active and its vertical sealing capacity is poor while its lateral sealing capacity is good; so this fault is a main conduit of petroleum migration in the Zhuzhuang area and has a good match with the stage of formation of petroleum accumulations. The distribution of fluid inclusions and tracing analysis of pyrrolic nitrogen compounds also support this. Study also indicates that fault 2 in the Caoshe fault belt is short-active and has a good vertical sealing capacity but a poor lateral sealing capacity; so this fault is not a conduit of petroleum migration. Fault F3 is long-active and has a weak vertical sealing capacity; so it is a preferred conduit of petroleum migration. In the late stage, petroleum migrated and was accumulated mainly through sand bodies and unconformities, which also matches well with the history of hydrocarbon generation and expulsion, the formation stage of accumulation and the analysis of pyrrolic nitrogen compounds.

Abstract:Abstract：The upper member of the Early Cretaceous Dalazi Formation in the Yanbian area, Jilin, is characterized by occurrence of oil shale. The oil shale in the upper member of the Dalazi Formation in the Songjiang basin is commonly grayish-brown or grayish-black and paper-sheeted and compact massive. The organic matter in oil shale is of sapropelic type and humus-saproptlic type with an oil-bearing rate of 3.8% to 6.2%. There are 7 beds of oil shale in the upper member of the Dalazi Formation. Of these, beds 2 and 7 are of commercial value; they are not persistent in attitude and their cumulative thicknesses increase from east to west and from south to north. The compact massive oil shale is developed in the Yangmutun area in the axial region of the Songjiang syncline and the Laopianpo-Dongshan area in the north limb of the syncline. The sheeted oil shale occurs in the Yangmutu-North Songjiang area in the south limb of the syncline and Shenglitun area. The upper member of the Dalazi Formation may be divided into two third-order sequences. Beds 2 and 7 are both of semi-deep lake-deep lake origin and formed in the highstand systems tract of sequences I and II respectively. The persistently layered lake water, algal blooming, semi-deep lake-deep lake, protracted, stagnant, anoxic, reducing environment and effective accumulation and preservation of organic material-all these were favorable for the formation of oil shale. However, repeated subaqueous fan deposition by gravity flows was disadvantageous for the formation of oil shale.

Abstract:Abstract：Tectonically located in the north Gangdise tectono-metallogenic belt, the Nyixung skarn iron-copper field in Coqên, Tibet, is composed of the superlarge Nyixung iron deposit and intermediate-sized Ri'a copper deposit. It was found during the regional geological survey of the 1:250000 Comai Sheet, Tibet, in the first-round of the land resource survey of the Qinghai-Tibet Plateau. The Nyixung iron-copper field originated in the process of major tectonic transition from plate subduction and collisional epeirogeny to Cenozoic intraplate orogeny of the Qinghai-Tibet Plateau. The metallogenic epoch is Late Cretaceous. It is a superlarge iron deposit with the largest ore potential in the north Gangdise belt. On the basis of the evaluation data from the rich iron and copper deposits in the Coqên-Ngamring area, the geological characteristics of the Ngixung iron-copper field in Coqên and its significance for ore prospecting and analyzed.

Abstract:Abstract：The uranium mineralization bed in the interlayer oxidation zone in the HAB area on the western margin of the Ordos basin consists of gray sandstone, which has good permeability and uranium sources and contains a fair amount of organic carbon as the reducing agent. The interlayer oxidation zone has a certain extent and shows good zoning. Uranium mineralization controlled by the transition zone at the sides of the interlayer oxidation zone is characterized by a large extent, multiple beds and a high ore grade, showing good ore potential for the area. The authors suggest that the future mineral prospecting work should focus on further controlling the distribution shape of the front boundary of the interlayer oxidation zone of the Yan'an and Zhiluo formations and tracing the size of the orebody.

Abstract:Abstract：The “Sanjiang metallogenic belt” in southwestern China is tectonically located in the convergence zone between the Indian plate and Yangtze plate. In recent years, breakthroughs have been made successfully in copper, gold and lead-zinc (silver) exploration in the south-central segment of the belt where magmatism was strong, metamorphism was extensive and mineralization types were highly varied. Based on geological, geophysical and geochemical studies of major large and medium-sized mineral deposits in the metallogenic belt in Yunnan, China, the paper discusses the integrated information ore-finding model and indicators and presents new ore-finding ideas and direction in terms of time and space.

Abstract:Abstract：Large numbers of coral and fusulinid fossils were collected from the strata originally assigned to the Upper Carboniferous Qiati'er Group in the Chalukou area of the northern Qiangtang block, West Kunlun, during geological mapping and cross-section measurements of the Hongshanhu area of the 1:250,000 Chalukou Sheet. Their ages were determined to be late Early Permian-early Middle Permian. These fossils provide a basis for the determination of the age of this sequence of strata, fill in a gap of the Early-Mid Permian strata in the Chalukou area of the northern Qiangtang block, West Kunlun, and offer new baseline information for the intensive study of the stratigraphic sequence framework in the northern Qiangtang block, West Kunlun.

Abstract:Abstract：Based on the sedimentary environment of the shallow groundwater aquifer and its vadose zone, the paper illustrates the decreasing trend of sodium and chloride ion concentrations from east to west in shallow groundwater in the Suzhou-Wuxi-Changzhou region. According to a data analysis, the ratio of rNa/rCl in shallow groundwater is closely related to the sedimentary environment of transgression and sedimentary history. The longer the freshening history of groundwater is, the higher the degrees of the cation and exchange adsorption between sodium ions adsorbed in aquifer media and calcium and magnesium ions in groundwater will be. As large numbers of sodium ions enter groundwater, the ratio of rNa/rCl is higher and higher.

Abstract:Abstract：The provenance of sediments in the western South China Sea (SCS) is less studied,and especially there is much dispute about the provenance of the central part of the sea area. Because of the absence of large river input,it is usually considered that the main material sources of the central part are the Red River in the north and the Mekong River in the south. In order to better understand the provenance in the western SCS,systematic surface sediment samples were collected and clastic minerals were analyzed. The results show that clastic minerals are mainly distributed in the continental shelf in the south and the slope in central part. Factor analysis shows that the south,central and north areas may be distinguished for the clastic minerals in the western SCS. The clastic minerals in the shelf of the south area consist predominantly of heavy minerals such as rutile,anatase,leucoxene,zircon,tremolite and staurolite and light minerals such as quartz,feldspar,which indicates that the protoliths are dominantly magmatic rocks and partly metamorphic rocks; those in the slope of the central area are mainly staurolite,tremolite,tourmaline,limonite,biotite and muscovite,which suggests that the protoliths might be mainly metamorphic rocks; and the clastic minerals in the slope of the north area are scarce and the characteristics of the mineral assemblage are not pronounced. The three areas not only show notably different mineral assemblage characteristics but also distinct boundaries between the areas,indicating that their provenances are markedly different. The provenance in the south area is the Mekong River and Kalimantan; the clastic mineral assemblage in the central area is in the main coincident with the metamorphic rocks exposed in large amount in the Indo-China Peninsula,suggesting that the provenance is mainly the Indo-China Peninsula rather than the Mekong River south of it and the Red River north of it.

Abstract:Abstract：Based on the SRTM3-DEM data and by using the ArcGIS platform, the authors calculated and analyzed the relief amplitudes and slopes of the Ordos area and its vicinity, established the correlation among the relief amplitudes, slopes and landslide hazard occurrence using regional landslide hazard survey data, and discussed the geomorphological significance of the relief amplitude analysis. The results show that in the study area landslides mainly occur in areas with relief amplitudes ranging from 200 to 300 m. The landslides in this amplitude interval account for 48.5% of the total number of landslides and 20.3% of the total surface area of the study area. Those areas have relief slopes ranging from 10° to 18°, and the landslides with this slope interval account for 46.7% of the total number of landslides and 30.5% of the total surface area of the study area. Geomorphologically the areas of frequent landslide occurrence correspond to monadnocks, loess tablelands and loess ridges. Analysis of topographic features of longitudinal and latitudinal profiles across the study area shows that the relief amplitude and slope have a good correlation with the occurrence and distribution of landslides. This correlation provides a new idea for assessments of regional landslide hazards and is of great significance to regional geohazard planning and prediction.

Abstract:Abstract：Based on the 1∶100,000 and 1∶500,000 topography maps, the authors investigated rivers (hydrology), snow lines, glacier heights and relationships of the lake area and mountain area at different heights in mountain lake basins on the Qinghai-Tibet Plateau. The area of plateau lakes is closely related with that of their catchment mountains (the elevations are >500-750 m above the present lake level in the central and western parts of the plateau and >250 m above the lake level in the eastern part of the plateau). These suggest that mountain precipitation is probably the main source of lake water and that its quality (low temperature) and quantity are the main factors for maintaining the size and stability of the lakes. Owing to these special hydrological characteristics, the mountain lakes on the plateau expanded more significantly than lowland and hill lakes during the warm-wet period in the geologic past. At 40-23 ka BP, the mountain lakes on the plateau underwent unusual expansion, which was probably because more moisture was transported to the mountainous areas and more low-temperature water flowed to and stored in the mountain lakes during the increase of monsoonal rain in the warm period.

Abstract:Abstract：The paper analyzes the grain-size distribution of riverbed alluvial deposits in Harbin, and on that basis, combined with the grain-size distribution of sand-dust fallouts, it discusses the impact of bare riverbed alluvial deposits on the sand-dust weather. The analytic results show the following：the >63μm particles of bare riverbed alluvial deposits constitute >84% of the components, while the <63 μm particles are rare and those <10μm are very rare; the content of silt-clay particles <63μm amounts to >90%. Both sand-sized coarse grains and silt-sized fine grains of riverbed alluvial deposits show no correlation with the grain size of sand-dust deposits and have no contribution or little contribution to the material composition of sand-dust storms. Restricted by the flying height and transporting distance of sand-sized (>63μm) coarse particles, particles of alluvial deposits of the bare riverbed cannot be transported over long distances when sand-dust storms happen; so they have little influence on the whole Harbin area. The sand-dust materials that really influence the whole Harbin area are silt-sized (< 63μm) particles, especially dust (<10μm). It is considered that what have major effects on the sand-dust weather in Harbin are surface soils and building soils in the city that contain voluminous fine particle materials. These sites are key areas that should be controlled for preventing the sand-dust weather in Harbin City.

Abstract:Abstract：Exploitation of coal resources in the Daliuta area, Shenmu, Shaanxi, inevitably causes the problems of mine environmental geology such as land collapse, ground cracks and lowering of the groundwater level; thus whether land collapse will intensified land desertification becomes a hot topic. Investigation indicates that during the last 20 years the land desertification in the whole Daliuta area and main mining areas therein shows a consistent evolutionary trend of gradual decrease of severely desertified lands and gradual increase of slightly desertified and non-desertified lands, and the land desertification in coal mining collapse areas has not been engraved. The authors studied the relationship between vegetation species and their covered rates, soil granularity, water content, vertical distribution of vegetation root systems at the vertical soil profiles in four coal mining collapse areas and two non-mining areas in the coal mine and conclude that coal mining collapses have no significant effect on land desertification and that the annual average rainfall of 415 mm may in the main meet the requirement for the moisture content for the normal vegetation growth in coal mining collapse areas. Such a conclusion provides a scientific basis for the prevention and control of land desertification during large-scale coal resources exploitation in mining areas.

Abstract:Abstract：It is difficult to select refuse landfill sites in karst areas and the present assessment method of refuse landfill site selection has many limitations. Therefore an improved assessment method of refuse landfill site selection is presented by the authors according to the construction purpose and basic principle of refuse landfill site selection, combined with the geo-environmental characteristics in karst areas. Its applications indicate that more suitable refuse landfill sites can be selected by this method in karst areas where refuse landfill sites are difficult to select by using the present method, and that the method is capable of solving the difficult problems of refuse harmlessness and reduction in karst areas.

Abstract:Abstract：Deep geophysical survey data are important information on the study of the lithospheric structure. However, data sharing was hindered by the characters of geoscience data such as multi-source, multidisciplinary and massive data. GIS can afford a new approach to data release because of its function of multiple discipline crossing and spatial data processing. The presentation and analytic methods of information in GIS depend on the data model; therefore it is important to construct a data model according with the need on data query and data analysis when the sharing platform was designed using the GIS technique. Several spatial data storage methods and main spatial data models are studied intensively. Finally, a data model is constructed for data release based on Geodatabase according to the characteristics of the deep geophysical survey data.